Grundfos Pump install location right?

[charless917]

Please take a look at my picture and let me know what I need to change. I need to add a few shutoffs and I think I need to get a PRV (static pressure is 80psi but think pressure from city main jumps up to 100-120psi need to get a better gauge to know for sure)

The main question I have is about the grundfos up10-16bn5\tlc. I have a 1/2 loop coming back to the hot water heater from the farthest sink. Originally there was only 1 water heater but was plumbed for 2. I added the second heater but left the pump on the first heater like it was. In either setup I just dont feel like it is right. I have seen other style grundfos pumps that attach directly to the hot out of the water heater, or where they come in at the drain valve but never seen a 1/2 line tee into the hot out. The main lines are 1". When testing this it does work but I have not been using the pump b/c I still need to insulate the lines.

There is a lot of different things in the pic that really need an explanation but Ill wait to see what responses I get before I go into too much detail. Example: Had to bypass cold water lines from softener, ill explain more if you think this is a major issue in the setup.

I know the picture isnt very good but thought it would help me when asking questions.

 

[charless917]

Also note that the (hot out) of the first heater is going into the (cold in) on the 2nd heater. The picture makes it look like its switched.

 

[LiQuId]

You should have the recirc tied into the cold inlet of the hwt, and there needs to be a proper loop to circulate. what your picture indicates is no return loop simply a pump installed and dead heading on the main hot. the pressure is jumping because the pump is adding pressure to the line.

this is going off of your drawing.

 

[johnjh2o]

If your designated recirculating line is connected to the hot water line at the furthest fixture from the heater? Then to make it work the recirculating line along with the pump should be connected to the bottom of the 75 gallon heater. There should also be a check valve installed in the recirculating line at the heater. The only other problem you may run into is that you have two branches on the hot line coming of at the heater. Only one of these lines will recirculate and that would be the one that has the recirculating line connected to. One other problem that I'm seeing is it looks like the hot water line that connects between the heaters looks like it's connected to the hot side of the 50 gallon heater. It should be connected to the cold side then feed the system from the hot side.

John

 

[charless917]

Yeah the drawing isnt the best. The recirc line comes from the farthest sink and is a proper loop, just didnt draw everything past a certain point. Also the hot and cold lines coming off of the heaters are going in and out the correct places, it just looks reversed b/c I was trying to make the drawing easier to see.

What I was thinking was that it made more sense to have the loop coming into the cold line. I wouldnt have to buy anything extra to do it, just move it. Do you think it makes a difference if it came in from the cold line on top or from the drain valve? To me I dont see the difference unless I was trying to do gravity feed and then it would have to come into the bottom.

I do have a check valve on the return loop. Thanks for the responses.

 

[speedbump]

I once built a house and ran a recirc line from the furthest end of the house back to the water heater and ran it into the bottom of the heater. After getting my first electric bill, I then insulated the pipes. One inch down and 1/2 inch back. No pump, the water would cool enough to auto circulate and I had very hot instant water at the furthest bathroom as well as the other two.

 

[charless917]

Once I get the lines insulated I was think about trying gravity and not have the pump on but this is a pretty large 2 story house (5,000-6,000 sqft) about 100ft long so Im not sure how well it would work out.

IF I was to connect the return loop to the water heater near the bottom I would just connect it to the drain valve correct? What is the best method for making this connection? Would I remove the plastic valve and connect it with a nipple or something like that. Not sure if I mentioned it but all my plumbing is PEX

 

[johnjh2o]

Remove the valve and install a nipple and a tee. Use one branch of the tee for return loop and install the drain valve into the other branch. It should be a 3/4" taping on the bottom of the tank.

John

 

[charless917]

Sounds good I'll try that out. Thanks for the help everyone. If you see anything else that I should be concerned with please let me know. I'm trying to get everything I need then do it all at once.

 

[charless917]

Would there be an issue using a outlet timer on the pump? It has a timer built in but it only allows for everyday to be set to the same. My weekends are very different than my weekdays. I thought I could put the pump on the always on setting and then use an outlet timer to turn it on and off to better match the hours of typical water useage.

 

[johnjh2o]

I don't see why it wouldn't work but I'm not an electrician. I wouldn't put to much faith in anything I say if it isn't round and have water flowing through it.

John

 

[LiQuId]

Doing that might interupt the Quantum flux capacitor in the pump causeing thermal deterioration in the matrix inhibitors..

 

[charless917]

Oh no not the Quantum flux capacitor

 

[zkirtlink]

you could install an outlet timer but it will throw off the time on the pump timer just keep it in the on possition. there is nothing wrong with the system you have going your pumping into the inlet side of the second heater. prefered actually it will help even out the load on the two heaters the second one will heat any return water that comes back cold where it is used to the first heater doing most of the work. yes insulater all hot lines that are accessable since they are all going to disipate heat and esspecially the main hot line and return for they both make it a full loop. the pump mounted directly on the hot side of the water heater that you are talking about is a comfort system the pump runs fairly low pressure. and there is a valve set that you install under the sink at the far end or multiple sinks if you have a spread out layout, they allow the cold water in the hot line to be pumped back into the cold water supply untill the hot water reaches the valve and it closes nice system if you you want a recerc. system but running the line is to pricey.

 

[johnjh2o]

you could install an outlet timer but it will throw off the time on the pump timer just keep it in the on possition. there is nothing wrong with the system you have going your pumping into the inlet side of the second heater. prefered actually it will help even out the load on the two heaters the second one will heat any return water that comes back cold where it is used to the first heater doing most of the work. yes insulater all hot lines that are accessable since they are all going to disipate heat and esspecially the main hot line and return for they both make it a full loop. the pump mounted directly on the hot side of the water heater that you are talking about is a comfort system the pump runs fairly low pressure. and there is a valve set that you install under the sink at the far end or multiple sinks if you have a spread out layout, they allow the cold water in the hot line to be pumped back into the cold water supply untill the hot water reaches the valve and it closes nice system if you you want a recerc. system but running the line is to pricey.

He has a designated return line he is not using the cold water line as his return.

John

 

[charless917]

Thanks for the replies. So far i have been told that i should run the return loop from the inlet on the first heater, or from the drain valve on the first heater, or leave it alone and have it coming into the inlet on the 2nd heater. Of course I like the sounds of not changing it but at this point it doesn't matter what I do. I have parts to do any one of those. Can I get one more vote on which setup is best? Also if I leave it alone and have the return loop going into the inlet of the 2nd heater would it be wise to put a check valve in on the output of the first heater. I would think that the water coming back from the return loop on a 1/2" line wouldn't have enough force to enter the first heater with the output being a 1" line but I thought cold water was "heavier" than hot and the return line is only about 20" from the outlet of the first heater. Just something I wasnt sure about.

And yes this is a dedicated return loop. All plumbing and heaters are 2 years old. The first 75 gallon heater is a much more expensive and higher quality heater than the 2nd heater if that makes a difference.

 

[zkirtlink]

I realize that john he mentioned he had seen the pumps mounted on the hot side outlet of a water heater I was justed giving some insight on what those systems were all about.

 

[zkirtlink]

I vote to leave it alone. If there was anything that you should do for this system I would say to plumb these water heaters in parallel wrather than in series. right now one is the slave to the other. it will work fine but the first unit will go out a lot sooner than the other.

 

[johnjh2o]

I realize that john he mentioned he had seen the pumps mounted on the hot side outlet of a water heater I was justed giving some insight on what those systems were all about.

Where did I say I have seen pumps on the hot side of a system with a designated return? And on the subject of pumps. They are not pumps they are circulators. They have a very small motor and all the do is create a very slight difference in pressure between the the supply and return side of the system. I have installed many of these systems with and without circulators. The best system you can have is a gravity system. It has no mechanical parts other then the check valve at the BOTTOM of the heater on the return line. The reason the return should be connected to the bottom of the heater is the water coming back from the return is colder then the water in the heater. You don't want that colder water coming into the top of the heater were it could go out into the system before being heated.

John

 

[zkirtlink]

the guy who is asking the questions said that he had seen the pump mounted on the top of the water heater on the hot side. currently it comes into the outlet side of the first heater and into the inlet side of the second heater through the dip tube to the bottom of the second heater. Less work involved with keeping it the way it is. Also for a home owner that is not a plumber when it comes down to a leaking water heater it will be much easier to just disconnect the top of the water heater, than to removing and replumbing the pump and return line, to the bottom.